Numerical Simulation of Consolidation Settlement of Pervious Concrete Pile Composite Foundation under Road Embankment

Abstract

Having the advantages of high permeability and high strength, pervious concrete is suitable for improving ground-bearing capacity. In the Yellow River Delta, a pervious concrete pile (PCP) composite foundation has been constructed to reduce settlement of an expressway embankment. To study the working mechanism of PCPs, a numerical model was constructed based on the finite-difference method and Biot’s consolidation theory, which was validated by data from in situ tests. The excess pore-water pressure, pile–soil stress ratio, lateral displacement, and settlement of the PCP composite foundation under the loading of the road embankment were numerically calculated and compared with those of gravel pile and low-grade concrete pile composite foundations. Comparisons show that the dissipation of excess pore-water pressure in the PCP composite foundation was fastest, which implied that PCPs can significantly mitigate the development of excess pore-water pressure and thus enhance subsoil strength. Furthermore, the PCP composite foundation showed minimal postconstruction settlement and lateral displacement. Therefore, PCP is particularly suitable for reinforcing subsoil that has low strength and poor permeability.